The present invention relates to draw-pull window shades or blinds for use in residential or commercial applications. The shade mechanisms disclosed herein are ideally disposed to applications involving nonrectangular window shapes such as peaked, diagonal, or triangular frames, arches, arcuate sections, and other partial or full elliptical forms.
This invention fills a need for well constructed and aesthetically pleasing shades and blinds, for interior or exterior application, for nonrectangular window shapes or other openings increasingly being used in modern residential and commercial construction. Such shapes can include triangles, pitched tops, peaks, arches, arcuate sections, and full or partial elliptical forms. Such window shapes lend great character to modern residential and commercial architecture. However, owing to this same character, these windows are extremely difficult to shade in a manner which is at once aesthetically pleasing, fitted to the shape of the frame, and structurally sound. Several attempts have been made to address this challenging problem, but results have heretofore been inadequate.
With pitched, peaked, and triangular windows, the difficulty of providing a workable shade lies in the inability to adequately cover the acute angular portion at the window""s apex. Stop-gap solutions have included covering only the rectangular portion of the window with a conventional shade leaving the angular apex exposed. In situations wherein the angle of the apex is less severe, a top rail has been installed along the length of the pitched lintel and the shade or blind material has been trimmed to fit the angle and attached to this rail. However, the lower rail of the shade upon which the material stacks when raised must be shorter than the top rail in order to travel through the narrower rectangular portion of the frame. This means that the lower rail must either stop its ascent at the cusp of the pitched portion, leaving the angular apex covered, or only one side of the lower rail may continue to be raised toward the apex. This is an undesirable solution because the shade material is subjected to the stress of being pulled toward the stationary end of the lower rail, which being shorter in length than the upper rail, its opposite end will not coincide with the apex when fully drawn. Because of this the shade material is likely to bunch at best and tear at worst. Additionally, either two draw cords or some other tension relieving method is required for the differing travel distances of each side of the lower rail.
Another detraction to present offerings in pitched or triangular window shades is that they are generally mounted in the lintel of the window frame rather than the sill. In most applications such windows are placed higher on walls toward the peaks of roof lines to accentuate the building architecture. Therefore when one looks out of these windows, one must look up at them. With shades of prior manufacture installed and opened, one sees a morass of mounting equipment and bunched shade material at the lintel of the window instead of the more aesthetically pleasing lines of the window itself. In many of these applications it would be preferable to place the mounting equipment and folded shade material on the sill which obscures the lower part of the window anyway when one is looking up at the window from a position below.
Even fewer options were available for covering windows with arched shapes until the advent of accordion pile and honeycomb shade materials. These materials allow for various degrees of arched shapes to be covered using a fan method. In those designs, the pleated or honeycomb material is constricted at one end while the opposite end is splayed open to fill the arch. Although such solutions generally cover the window, there are significant aesthetic drawbacks. First the bunching of the material at the point of constriction can be unsightly. This bunching also results in the folds of the material extending radially which is usually in marked contrast to the blinds on adjacent windows in which the folds are generally horizontal. This can be visually dissonant. Further, a circular opening remains at the pivot point, due to the limitations of bending a straight edge into an arc, which must be obscured by some additional facade.
The present invention is a significant improvement over prior alternatives and accomplishes the desired end with a more aesthetically pleasing appearance.
Schnebly (U.S. Pat. No. 4,934,436) (Schnebly I) discloses shade systems for covering arched windows. In one embodiment, pleated or honeycomb fabric is trimmed into an arched configuration and is fixedly mounted to the sill. It is raised to cover the window by means of a continuous cord under constant tension attached at a fixed point to the top pleat of the shade material. A problem with this design arises from the stress placed upon a single point of the shade material engaged for raising and lowering its entire weight and structure. Similarly, the outer edges of the top surface of the shade are not supported. This requires a limitation of available shade materials to those with sufficient horizontal stiffness or structure, such as honeycomb, to prevent the sides of the shade from sagging. In practice, even the more rigid materials droop over longer spans. Additionally, when lowered, the pleats, if more rigid, tend to splay out in a fan shape rather than lay flat.
Schnebly I also discloses a system for covering arcuate windows via two hinged edge rails. Each pleated edge of pleated or honeycomb shade material is attached to each edge rail respectively, in essence forming a fan with the hinge providing ability to adjust the splay of the fan. In one embodiment the fan must be manually placed within or removed from the window frame which limits its usefulness, especially for windows placed high on a wall in a room with a vaulted ceiling. Another embodiment employs a drawstring, but its application is limited to windows of acute angles as gravity is required to collapse the fan and return the shade to a closed position. With both designs there are the additional limitations of bunching of shade material and a hole in the coverage of the shade material as it bends out around the hinge. This hole is also aesthetically displeasing and requires some additional shade or ornamentation to disguise it.
Schnebly et al. (U.S. Pat. No. 5,002,112) (Schnebly II) provides additional embodiments for covering arched and arcuate windows. These consist of fixed fans of pleated or honeycomb material supported on fixed arcuate frames with finger-like extensions for engaging the pleats or honeycombs to supply the necessary arcuate splay and some minimal vertical support. These systems are static and must be manually placed within or removed from the window frame, thereby severely limiting their usefulness. As with Schnebly I, applications of these systems are limited to fairly rigid, pleated or honeycomb shade materials as other materials would not have the stiffness required to support their own weight in such fan-like configurations.
Judkins (U.S. Pat. No. 4,518,025) discloses a system for clamping the top edges of irregular shaped shades to the upper rail mounted in the lintel. Pitched and arched shades are particularly shown. This system does not, however, allow the shades to be entirely raised. Retraction is limited to portions covering rectangular areas only. When an irregular section is reached, the shade can be opened no further because either the bottom rail encounters the lintel on one side or it is unable to travel through the narrowing frame of an arched section.
Niemeijer et al. (U.S. Pat. No. 5,092,383) discloses shade mechanisms for covering rectangular windows with pitched or arcuate lintels. The invention uses pleated or honeycomb shade material as well and is concentrated on an intricate weaving system of drawstrings through the shade material and a guide system to continue to evenly raise the shade through the pitched and arcuate sections without binding once the rectangular window section is passed. A middle rail is used at the threshold between the rectangular and pitched or arcuate sections. The lower shade material stacks against the underside of the middle rail which is hinged on one end to the lower end of the upper rail along the lintel. The middle rail in a pitched embodiment travels to finally rest against the upper rail. Niemeijer also considers using flexible middle and bottom rails, e.g., made out of flexible plastic, to conform to arcuate lintels when the shades are drawn fully open. Problems with this invention are similar to those previously described: the shade material in the pitched or arcuate portion is not horizontal, but bunched and fanned; as the middle rail travels through the angle on its hinge, the shade material is subjected to tension, stress, and possible tearing due to the difference in width between the rectangular section and upper rail; and the shade material available is limited to rigid pleated or honeycomb structures. In the arcuate configuration utilizing flexible rails, the shade material is subject to even more tension and stress.
Wolf et al. (DE 4037264A1) similarly discloses a hinged middle rail system for covering a pitched top portion of an otherwise rectangular window. The invention is substantially similar to that of Niemeijer et al. and therefore shares its problems and limitations.
Schxc3x6n (U.S. Pat. No. 5,197,526) (Schxc3x6n I) discusses shades for shading triangular, trapezoidal, polygonal, or semicircular windows using pleated or gatherable shade material. In all of the various embodiments shown and discussed, the basic principal revealed is the use of guide cords running through the lateral edges of the shade material to keep it horizontally stretched across the window frame. Additional draw cords are used, spaced appropriately along the horizontal width, to raise or lower the shade. This solution is both practically limited and aesthetically unpleasing. The Schxc3x6n I invention creates severe bunching of the shade material at the application points of the draw cords. Also inherent in the design, the lateral edges of the shade material drag behind and lower along the guide cords. The shades of this disclosure can never be fully and uniformly raised and they create great tension and stress on the shade material, potentially ripping or tearing it.
Schxc3x6n et al. (EP 0058459) (Schxc3x6n II) discloses a shade for use in a frame with a non-horizontal lintel. The top of the shade is trimmed diagonally and appears to be secured to the upper rail by a cord woven along the diagonal through openings in the edge of the shade material. Schxc3x6n II states that this allows for freedom of movement along the top edge as the bottom rail is tilted while bringing the longer side of the shade against the upper rail. This cord system does not, however, prevent the bunching of shade material on one side nor reduce the stress on the shade material between the dual drawstrings running lengthwise through the material to the bottom rail. When the bottom rail begins to tilt, the formerly uniform distance between the draw cords progressively widens creating tension, stress, and potential tearing of the shade material in between.
Steiger (PCT/EP 92/00382) discloses a shade for triangular window segments composed of a shorter upper rail to which the top edge of the shade material is attached. The upper rail is raised and lowered via a cord system raising and lowering the shade similar to a boat sail. Guide cords threaded through openings on the lateral edges of the shade material keep the shade in the frame, guide cords along angled sides being tensioned to provide or remove slack as needed. Apparent limitations with this design include the inability to provide coverage at the apex of the window and the necessity for a separate shade or hinged middle rail as in Niemeijer to cover the lower rectangular portion of the window.
Scharfenberg (EP 0534261-A2) discloses a window shade for trapezoidal windows similarly incorporating a shorter top rail and tensioned lateral edge guide cords, as well as a tensioned cord along which the top rail manually travels to raise and lower the shade. Applications for this shade are limited to trapezoidal shapes; it is unable to operate in arched, triangular, or other pitched lintel situations.
Finally, Rupel et al. (U.S. Pat. No. 5,207,257) and Yamakawa (JP 404269919) each disclose a shade for a rectangular window frame using pleated shade material which by means of a separate drawstring collapses a hinged bottom rail upwards to create a decorative fan-shaped shade.
The present invention utilizes a unique new design for either the lower or upper rail on a window shade system called a sliding headrail. The sliding headrail allows a shade to be fitted exactly to a myriad of nonrectangular window shapes and to be opened or closed without placing undue stress upon the shade material or causing unsightly bunching of the shade material. In fact, the sliding headrail keeps shade material neat and flat within the window frame, and if pleated or honeycombed, maintains the pleats in their natural horizontal arrangement.
In one embodiment, the sliding headrail is composed of numerous sliding sections which allow the headrail to conform to the shape of most any nonrectangular window including pitches, peaks, triangles, trapezoids, arches, arcuate sections, or full or partial ellipses. Each section is composed of a thin, flat, rigid material, generally rectangular in shape. In the preferred embodiment, sections are connected to each other in an alternating overlapping/underlying manner by two pins or screws which are fixedly attached to a face of one section and glide in one or more slots in the opposing face of an adjacent section. Other means of attachment of the sections allowing both horizontal and vertical movement between the sections may be used as well.
Depending upon the shape of the window, the number and orientation of slots in the sliding headrail sections may vary. Sliding headrail sections for windows with straight sills or lintels may have only one slot per pair of pins to allow for strictly horizontal movement, relative to the sections, along the sections. For windows which have some curvature, at least one slot is angled with respect to the horizontal, relative to the sections, to allow for vertical movement between sections, thus creating a curved headrail. In situations where both the upper and lower portions of a window are curved, at least one slot may be arcuate which allows the headrail to reverse its curvature to fit the appropriate side of the frame. At least two pins are preferred to maintain the structure between the sections as one pin might simply create a freely rotating hinge or pivot.
Shade material is attached to the sliding headrail segments at various points via a novel shade leveling rod. In one embodiment, an individual shade leveling rod is a length of wire fixedly attached at each end along a sliding headrail segment. The length of the shade leveling rod is displaced from the headrail segment. The shade material is attached via an eyelet running through the shade material at a fixed point and around the shade leveling rod. The eyelet is therefore free to travel the length of the shade leveling rod. Although this particular embodiment of a shade leveling rod has been disclosed, any similar sliding attachment would work equally as well. Additionally, in some circumstances as for narrow windows, or windows with lintels with mild angles of pitch or curvature, a single headrail segment may suffice to support the shade material attached to a shade leveling rod.
The shade leveling rods allow the shade material to remain horizontally level regardless of whether the shade is partially or fully open or closed. This benefit is especially apparent when the shade material used is pleated. The regular spacing of attachment points along the edge of the shade material reduces the stress due to drawing the shade open or closed placed upon any one point, ensures the appropriate distribution of the shade in the frame, and prevents drooping of lateral ends. The shade leveling rod also prevents the stress associated with drawing shade material into nonrectangular areas such as pitches, peaks, and arches.
In addition to attaching the shade material along its top edge to the headrail segments, the shade material may be additionally or alternately supported by support rods. Support rods may be easily placed at various levels of the shade, either external or internal, such as lengthwise within a chamber of honeycomb shade material and attached to the headrail segments by cords on the back side of the shade material. When the window shade is raised, the cord attached to the support rods become taught and pull the rods up which help to distributively support the shade material. When the shade is lowered, the rods help to compress the shade material in the sill and prevent the shade material from bunching.
Another technique for attaching shade material to a headrail in a single headrail application is to use a shade elevating rod. The shade elevating rod is preferably inserted into the top chamber of honeycomb fabric or into a seam along the top edge of other shade material to provide distributed support to the shade material. In arched lintel applications, the shade elevating rod may be slightly arched as well to provide a snug fit for the shade material against the lintel. In appropriate applications, multiple shade elevating rods may be used. A novel system for threading a draw cord to obscure its presence in the lintel and preventing it from becoming entangled in the headrail hardware is also disclosed.
The window shade is not limited to the use of any particular shade materials, and can use virtually any window covering material depending on the appropriateness of the application. With obvious modifications to the strength of components used in construction and an appropriate choice of shade material, the present invention can be conformed for exterior applications as well.